BY THE OPTIMIST DAILY EDITORIAL TEAM
Most ocean cleanup efforts work on the same assumption: the problem floats. Skim the surface, collect the plastic, done. The trouble is that most marine litter doesn’t float. It sinks to the seabed, where it sits undisturbed and largely out of reach of the methods designed to catch it.
SeaClear2.0 was built for what those efforts leave behind.
How much litter ends up on the ocean floor?
“There’s a huge amount of litter that ends up in the sea,” says Bart De Schutter, a professor at Delft University of Technology and coordinator of both SeaClear and its successor. “Many projects target surface litter, but we look at the sea floor. It’s important to remove rubbish there, because it can contaminate the environment.”
Once plastic reaches the seabed, it doesn’t stay intact. It breaks down into smaller and smaller fragments, eventually becoming microplastics so fine they work their way into food chains and water supplies. Removing debris before that happens matters, because microplastics are notoriously hard to collect once they form.
SeaClear2.0 operates under the EU’s Mission: Restore our Ocean and Waters, which targets cutting marine litter by around half by 2030.
The robot fleet doing the heavy lifting
Surface drones that scout first
The operation starts above the waterline. Uncrewed surface vessels move into target areas while aerial drones survey the seabed below, logging the locations of debris, things like bottles, tires, metal fencing, and ship components, before anything goes down to retrieve it.
Underwater robots do the collection, grabbing debris or vacuuming it up. They can distinguish litter from rocks, plants, and marine life, which is genuinely difficult when visibility is low. A crane-mounted smart gripper handles heavier objects.
A floating bin lorry for the deep
Researchers are also testing an autonomous barge that functions as a floating depot, collecting waste from the drones and hauling it back to shore rather than making individual round trips.
“In tests, we’ve already removed rubber tyres, metal fences and parts of ships,” De Schutter says. “Using a crane on the surface vessel, we can lift even heavier objects.”
Before this system existed, all of it required divers. Heavy debris meant attaching cables underwater and hauling things to the surface by hand. Slow, expensive, and physically demanding work that the robot system is designed to replace.
Where the project stands now
Initial tests have been completed in Marseille and Germany. Venice, Dubrovnik, and Tarragona are next, three sites with different enough seabed conditions to give the technology a real stress test.
The system isn’t done. “We’re not exactly where we want to be yet,” says Yves Chardard, CEO of Subsea Tech, a French company partnered on the project. “But we’re not far off. The goal now is to streamline the technology.”
SeaClear2.0 is due to wrap in late 2026, with the team aiming to have cleanup crews working alongside local authorities across Europe by then. There’s one more application being explored on the side: it turns out the same detection systems that find buried debris may also work for locating unexploded mines left on the seabed from earlier wars. A practical bonus nobody planned for at the start.
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